The Reward Flier contains information about the competition that is going on in Cryptids Island. It says that anyone who can get any evidence or proof of the existence of a cryptid will be rewarded $1,000,000. You can also examine it to get further information.
How to Get the Reward Flier
The Reward Flier is automatically be given to you once you arrive in the Cryptids Island, just walk to the right and a man will tell you about the competition that is going on. And you will received Reward Flier, you can examine it to see its content. This should also be the first item that you will get in this island.